1. Field of the Invention
A pressure controlled valve apparatus for use with a catheterized bladder of the like to selectively control fluid flow therefrom at a predetermined pressure.
2. Description of the Prior Art
Various efforts have been made to control the bladder volume of patients undergoing bladder catheterization. A common procedure to obtain continuous drainage of urine from the urinary bladder employs a catheter passed transurethrally and retained in the bladder by standard and conventional devices. Generally such continuous drainage is without periodic filling and emptying of the bladder.
Unfortunately such procedures or techniques exhibit several significant shortcomings. The urinary bladder is a hollow distensible organ requiring alternate filling and emptying to maintain the tone of the muscular walls. Such periodic filling and emptying of the bladder is one of the major mechanisms by which the concentration of bacteria in the bladder is kept at biologically acceptable levels. This mechanism dilutes the bacteria present in the bladder with sterile urine from the ureters with periodic and complete emptying of the bladder. If the bladder is kept from emptying completely, although still allowed to partially expel the contents periodically or continually, the growth of bacteria in the bladder may be of such magnitude that infection will result.
Moreover such indwelling bladder catheters generally do not conform to the contracted shape of the bladder so that "foley tip necrosis" of the dome of the bladder may result. Such a pressure ischemic ulcer of the dome may be the portal by which bacteria enter to infect the bladder. Such infections, common in patients with indwelling catheters, are caused when the dome of the bladder collapses or is drawn down over the indwelling catheter.
Numerous attempts have been made to improve such drainage systems. U.S. Pat. Nos. 2,602,448 and 2,860,636 show drainage and irrigating units utilizes a siphon in combination with a reservoir to provide cycle draining of the bladder. However, these systems like other siphon systems, require a loop be fed at a predetermined height above the patient's bladder to create two siphon legs which will create the pressure at which the siphon will empty the bladder. Pressure release is controlled by raising the height of the device on a bedside support and is very precise and subject to variations by a shifting patient and preventing patient from moving around while the catheter is in place.
U.S. Pat. No. 3,598,124 discloses a siphon leg controlled by attaching the catheter to a support at predetermined adjusted height to vary the pressure at which the bladder will drain with a flutter valve near the patient to break the siphon action of the system once the bladder has drained.
U.S. Pat. No. 4,230,102 discloses a device for the draining of a urine bladder using a T-joint placed on a catheter with a pressure membrane attached thereto in a large casing for actuating a pressure switch which in turn actuates an electric motor driving a gear train and cam. A cam follower is spring loaded to clamp the catheter for two minute cycles upon actuation by the pressure switch to drain the bladder.
U.S. Pat. No. 3,768,102, shows an implantable artificial urethal valve, while U.S. Pat. No. 3,642,004 discloses a urethal valve employing an electrically actuated solenoid. U.S. Pat. No. 3,419,009 discloses a vented surgical drainage tube for bladder irrigation utilizing an electrical control system with a timing cam.
U.S. Pat. No. 4,424,058 shows a drainage control valve apparatus that utilizes a pressure relief valve opening upon a predetermined fluid pressure and a liquid column to hold the pressure relief valve open under the weight of the liquid column escaping past the pressure relief valve to apply a negative pressure to the back of a pressure relief valve element.